Environmental noise from wind farms, prediction and measurements

Abstract

Although mechanical noises of wind turbines have been eliminated with the development in their design, aerodynamic noise generation during operation is inherent to them in nature. Their major acoustic emission occurs in low frequencies. To predict noise levels in the environment associated with the operation of stationary sources-wind turbines included-, the methodology of ISO 9613-2 is usually recommended. It is not only a standard method of calculation but it is also the recommended methodology in the European Union. However, under some conditions (such as a stable atmosphere) the predictions of this method may significantly underestimate the expected environmental noise levels. Lately, other methodologies of prediction that take in account atmospheric stability have been developed. Nevertheless, predictions from different calculation methods do not always result on the same sound pressure levels. Different prediction methods are compared in this article. Their accuracy is then evaluated by checking env...